Both molecular structure of macromolecular materials and subsequent processing of these materials dictate resulting material properties. In this work novel synthetic strategies combined with detailed analytical methodology reveal fundamental structure-processing-property relationships in thermoplastic polyesters, thermoplastic polyurethanes, covalently crosslinked acetal functionalized networks, and small molecule surfactants. 4,4’ dimethyloxybisbenzoate afforded a series of novel polyester structures, and the incorporation of this monomer both increased the Tg and decreased the crystallinity in cyclohexane dimethanol based polyesters. Solubility and dynamic light scattering experiments combined with oscillatory rheology techniques provided methodology to validate polyurethane extrusion in commercial polyurethanes. Acid catalyzed hydroxyl addition to vinyl ethers provided two families of acetal functionalized poly(ethylene glycol hydrogels). Stoichiometric control of binary thiol-acrylate polymerizations afforded hydrogels with both tunable mechanical properties and predictable degradation profiles. Following this work, a photoacid generator catalyzed cationic catalysis provided acetal functionalized organogels whose mechanical properties were predicted by excess vinyl ether monomers which underwent cationic polymerization under the same reaction conditions that yielded acetal functionalization. Time resolved FT-IR spectroscopy provided new understanding in hydroxyl vinyl ether reactions, where both hydroxyl addition to a vinyl ether and vinyl ether cationic polymerization occur concurrently. This work inspired research into new reactive systems for photobase generator applications. However, current photobase generator technologies proved incompatible for carbon-Michael reactions between acetoacetate and acrylate functionalities as a result of uncontrollable acrylate free radical polymerization. The fundamental knowledge and synthetic strategies afforded by these investigations were applied to small molecule surfactant systems for fire-fighting applications. Triethylsilyl-containing zwitterionic and cationic surfactants displayed surface tensions lower than hydrocarbon surfactants, but larger than siloxane-containing surfactants. For the first time, oscillatory rheology and polarized optical light imagine rheology highlighted shear-induced micelle alignment in triethylsilyl surfactants, which provided more stable foams than zwitterionic analogues. The knowledge gained from these investigations provided fundamental structure-processing-property relationships in small molecule surfactant solutions applied as fire-fighting foams. This discovery regarding the effect of self-assembled structures in foam solutions informs the design and analysis of next generation surfactants to replace fluorocarbon surfactants in fire-fighting foam applications.

High-performance polymers (HPPs) have dominated the synthetic polymer market for critical applications, including aerospace, energy, microelectronic, and transportation industries since their development in the mid-1900s. Although their structures share general similarities, such as high aromatic content, HPPs offer wide structural variance providing amorphous and semi-crystalline systems. As a result, conventional processing methods employed for HPPs are energy intensive and accessible part geometry is limited; often requiring subsequent subtractive techniques, i.e.,; milling, to obtain high quality and performant parts. Traditional processes were challenged by the emergence of advanced manufacturing techniques, such as 3D printing, which spurred significant academic and industrial interest. In the first project, poly(arylene ether sulfone)s (PSU) were chemically modified post-polymerization to enable ensuing photopolymerization of high molecular weight (Mn) PSU solutions into complex shapes with vat photopolymerization (VP). The resulting materials exhibited fast crosslinking, but low and unstable plateau storage moduli (G’). To overcome this, addition of low molecular weight crosslinker and precise control of UV irradiation increased crosslink density and inhibited photodegradation events, respectively. Ultimately, these modifications facilitated the first report of PSU structures fabricated with a UV-assisted AM modality. Next, 3D printable polyimides (PIs) were synthesized and extensively characterized to further expand the HPP AM toolbox. However, fully aromatic PIs pose a significant challenge as most are insoluble, intractable, and lack any discernable viscous flow. AM PIs were produced using two distinct approaches previously reported in the Long research group; the pendant salt approach imparts photoreactivity through the neutralization of the poly(amic acid) intermediate with small molecule amino-acrylates while the polysalt approach employs dicarboxylate-diammonium ionic organization to template the PI amongst an acrylic scaffold. Through the pendant salt approach, water soluble PI precursors enabled facile AM of complex structures, which served as efficient carbon precursors. The polysalt approach offers superior solid content and solution viscosities; however, these highly polar solutions initially exhibited deleterious side reactions. Application of acid-base fundamentals provided novel printable polysalt solutions with extended shelf-life, reproducible printing, and simplified processing. The relationships established from these projects expanded the applications of the most performant synthetic polymers and will inform future polymer design for additive manufacturing.